Environmental issues and health-benefitting design strategies have raised interest in natural and renewable building materials, resulting in an increased focus on the use of wood in built environment. The influence of wooden materials on measured and perceived indoor environment quality (IEQ) has gained attention during the past few decades, with a growing number of studies having explored the issue. This review was conducted to examine and summarise the body of research on the influence of wooden interior materials on IEQ, with an emphasis on the following themes: emissions of chemical compounds, moisture buffering of indoor air, antibacterial effects, acoustics, and psychological and physiological effects. This review found that wooden interior materials exert mainly positive or neutral effects on IEQ, such as moderating humidity fluctuations of indoor air, inducing positive feelings in occupants, and inhibiting certain bacteria. Negative effects on IEQ are limited to volatile organic compounds emitted from wood. The odour thresholds of some aldehydes and terpenes are low enough to affect the perceived IEQ. Additionally, concentrations of formaldehyde and acrolein may under certain conditions cause adverse health effects. Further studies are needed to better understand these phenomena and take advantage of the beneficial effects while hindering the unpleasant ones.

The emissions of volatile organic compounds (VOCs) from building materials may significantly contribute to indoor air pollution, and VOCs have been associated with odor annoyance and adverse health effects. Wood materials together with coatings are commonly used indoors for furniture and large surfaces such as walls, floors, and ceilings. This leads to high surface‐to‐volume ratios, and therefore, these materials may participate remarkably to the VOC levels of indoor environment. We studied emissions of VOCs and carbonyl compounds from pinewood (Pinus sylvestris) boards of 10% and 16% moisture contents (MC) with three paints using small‐scale test chambers (27 L). The emissions from uncoated pinewood and paints (on a glass substrate) were tested as references. The 28‐day experiment showed that the VOC emissions from uncoated pinewood were lower from sample with 16% MC. Painted pinewood samples showed lower emissions compared to paints on glass substrate. Additionally, paints on 16% MC pinewood exhibited lower emissions than on drier 10% MC wood. The emissions from painted pinewood samples were dominated by paint‐based compounds, but the share of wood‐based compounds increased over time. However, we noticed differences between the paints, and wood‐based emissions were clearly higher with the most permeable paint.

Stricter energy efficiency requirements of buildings have raised concerns about their effects on indoor air quality (IAQ). We studied measured and perceived IAQ in three low-energy wooden test buildings using three ventilation levels (0.5, 1.0, and 2.0 (dm³/s)/m²). IAQ measurements included VOC (volatile organic compounds) air sampling and continuous measurements of several IAQ indicators. Perceived air quality (PAQ) was investigated with a sensory panel of untrained volunteers. The results show that the TVOC (Total VOC) concentrations were relatively low in two of the buildings already at the beginning of the study (100–141 µg/m³), and the concentrations decreased in all test buildings when ventilation was increased from the lowest level. The third building made of pinewood timber showed higher VOC concentrations (340–857 µg/m³), especially for terpene compounds that are generally present in pinewood emissions. In the PAQ assessment, the percentage of people dissatisfied (PD) with the air quality decreased with increased ventilation in all studied buildings. However, at the lowest and highest ventilation, the pinewood building had the second-lowest PD despite higher VOC levels. The findings of this study can be utilized in interpreting the effects of ventilation design and material selection on IAQ in low-energy buildings.

Indoor radon is a major indoor air pollutant and the second leading cause of lung cancer. In Finland, uranium-rich bedrock combined with the development of highly airtight nearly zero-energy buildings (nZEB) increases the risk of indoor radon accumulation. As empirical evidence on the real-world performance of IoT-enabled radon control strategies is limited, this study investigated the effectiveness of sensor-integrated demand-controlled ventilation (DCV) systems in regulating indoor radon concentrations in three Finnish nZEB schools. Continuous radon monitoring was conducted over two months in 15 classrooms across the schools equipped with sub-slab ventilation. Each school employed a different ventilation control strategy: CO2-based DCV with individual classroom airflow adjustment (School 1), scheduled on/off ventilation (School 2), and CO2-based DCV with the worst-case space airflow adjustment at the service area (School 3). Radon concentrations were measured using RadonEye RD200 monitors. All schools maintained radon concentrations below the Finnish design target (200 Bq/m3) and the national action level (300 Bq/m3). Continuous airflow strategies (School 1 and School 3) maintained low, stable concentrations, whereas School 2 controlling strategy led to overnight radon accumulation, particularly in ground-floor classrooms. Morning flush cycles reduced concentrations below the WHO reference level (100 Bq/m3) during occupied periods, although higher exposure risks were still observed in School 2. Constant background ventilation resulted in a higher proportion of values below the sensor detection limit (9.1 Bq/m3), reaching 86.26% in School 1 and 96.40% in School 3, compared with 53% under the School 2 ventilation controlling strategy.